Current version supports saving and loading customized section when you set play-in/out and save it as modifed one before you exit from selected song. Then when you load next time modified one, your modified section (play-in/out, tempo, etc..) will be played as before. But saving modifed work can not be done for multiple versions. If we can save it in multiple versions such as modifed1, modifed2..... then your requrirements will be satisfied. Let's think about this kind of expansion.